From The Crucible (http://forums.interealms.com/shaman/showthread.php?threadid=20190&mode=linear&perpage=40&pagenumber=3), a posting about healing changes, and slow immunity, that are on Test:

Just to expand a bit on what Brenlo said:

The healing adjustments that are in development on test will most likely include an increase in the power of shaman Heal over Time spells. The healing changes in general are aimed at significantly reducing the number of situations where a cleric is the only viable healer in 6 man group situations. While we certain maintain that clerics should be the best at healing, it is unfair to expect them to be the only adequate healer in a single group setting.

The frequency of slow immune NPCs in Gates is also being looked at, and there is the possibility of some adjustment in certain areas if we find it necessary. Although this will likely only apply to a few specific areas where the concentration is especially high.